diff --git a/lua/plugins/codecompanion.lua b/lua/plugins/codecompanion.lua
new file mode 100644
index 0000000..0e4db39
--- /dev/null
+++ b/lua/plugins/codecompanion.lua
@@ -0,0 +1,86 @@
+return {
+	"olimorris/codecompanion.nvim",
+	version = "^19.0.0",
+	dependencies = {
+		"nvim-lua/plenary.nvim",
+		"nvim-treesitter/nvim-treesitter",
+	},
+	opts = {
+		adapters = {
+			acp = {
+				hermes = function()
+					local adapter = require("codecompanion.adapters").extend("codex", {
+						name = "hermes",
+						formatted_name = "Hermes",
+						commands = {
+							default = {
+								vim.fn.exepath("hermes") ~= "" and vim.fn.exepath("hermes") or "hermes",
+								"acp",
+							},
+						},
+						defaults = {
+							auth_method = "openai-codex",
+							timeout = 20000,
+							mcpServers = {},
+						},
+					})
+
+					-- Hermes resolves credentials from its own configuration.
+					adapter.env = {}
+					return adapter
+				end,
+				extend = {
+					codex = {
+						defaults = {
+							auth_method = "chat-gpt",
+						},
+					},
+				},
+			},
+			http = {
+				extend = {
+					openai_responses = {
+						schema = {
+							model = {
+								default = "gpt-5.6-terra",
+							},
+						},
+					},
+				},
+				openai_terra = function()
+					return require("codecompanion.adapters").extend("openai_responses", {
+						name = "openai_terra",
+						formatted_name = "OpenAI: GPT-5.6 Terra",
+						schema = {
+							model = {
+								default = "gpt-5.6-terra",
+							},
+						},
+					})
+				end,
+				openai_luna = function()
+					return require("codecompanion.adapters").extend("openai_responses", {
+						name = "openai_luna",
+						formatted_name = "OpenAI: GPT-5.6 Luna",
+						schema = {
+							model = {
+								default = "gpt-5.6-luna",
+							},
+						},
+					})
+				end,
+			},
+		},
+		interactions = {
+			chat = {
+				adapter = "hermes",
+			},
+			inline = {
+				adapter = {
+					name = "openai_responses",
+					model = "gpt-5.6-terra",
+				},
+			},
+		},
+	},
+}